Unit 3 - Life On Earth

Question 1

What is meant by the term abiotic factor?

Answer 1

Non-living things.

Question 2

What is meant by the term biotic factor?

Answer 2

Living things.

Question 3

Give examples of abiotic factors:

Answer 3

• Light Intensity
• pH
• Temperature
• Moisture level

Question 4

Give examples of biotic factors:

Answer 4

• Disease
• Predators
• Food
• Grazing

Question 5

What is meant by the term biome?

Answer 5

The geographical area of the planet that contains distinctive communities of fauna (animals) and flora (plants).

Question 6

What is meant by the term Niche?

Answer 6

A role than an organism that plays within a community.

Question 7

What is meant by the term habitat?

Answer 7

The place where the organism lives.

Question 8

What is meant by the term Population?

Answer 8

The total number of one species.

Question 9

What is meant by the term community?

Answer 9

All the population of plants and animals in an ecosystem.

Question 10

What is meant by the term ecosystem?

Answer 10

All the community of living things and their habitat.

Question 11

What is meant by the term biodiversity?

Answer 11

A total variety of all living things on earth.

Question 12

What does a pyramid of biomass show?

Answer 12

A pyramid of biomass shows the total mass of organism at each level in the food chain.

Question 13

What does a pyramid of numbers show?

Answer 13

The pyramid of number shows the total number of organisms.

Question 14

What does a pyramid of energy show?

Answer 14

A pyramid of energy shows the total energy at each level.

Question 15

What do organism need nitrogen for?

Answer 15

To make proteins.

Question 16

What are the four different types of bacteria and what are their functions?

Answer 16

•Nitrogen fixing bacteria
-converts nitrogen gas to nitrate.
•Decomposers (bacteria and fungus)
-convert pro town to ammonium compounds.
•Nitrifying bacteria
-some covert ammonium compounds to nitrate and some concert nitrite to nitrate.
•Denitrifying bacteria
-covert useful nitrate to nitrogen gas

Question 17

What are nitrification and denitrification carried out by?

Answer 17

Decomposers

Question 18

What do Decomposers (bacteria/fungus) use as an energy source?

Answer 18

They use dead plants and animals as an energy source.

Question 19

What is meant by the term intraspecific competition?

Answer 19

Intraspecific competition occurs when the individuals of the same species compete for exactly the same resources.

Question 20

What is meant by the term interspecific competition?

Answer 20

Interspecific competition occurs when the individuals of the different species compete for exactly the same resources.

Question 21

What is meant by the term adaptation?

Answer 21

An adaptation is a characteristic possessed by an organism which make it well suited to its environment.

Question 22

What is meant by the term natural selection?

Answer 22

Natural selection is a process where organisms which are better adapted to their environment survive and breed. These organisms which are less well adapted doe before they reproduce.

Question 23

What is meant by the term indicator species?

Answer 23

An organism whose presence or ensemble can be used to show the levels of pollution in the environment.

Question 24

What is meant by the term biological control?

Answer 24

Biological control is an alternative to using pesticides that can be harmful to the environment.

Question 25

What is meant by the term GM Crops?

Answer 25

Genetically modified crops is crops that have had their genetic information (DNA) changed to improve their characteristics.

Question 26

What is meant by the term bioaccumulation?

Answer 26

Bioaccumulation means when harmful chemicals can enter the food chain and their level can rise.

Question 27

How are new species formed?

Answer 27

Initial population is separated. Different mutation occurs at am each Subpopulation. Natural selection occurs. Subpopulation are no longer able to interbreed to produce a fertile offspring.